Portion of a shoe sole



FIG. 1 is a bottom plan view of a portion of a shoe sole showing my new design;

FIG. 2 is a first perspective view thereof; and,

FIG. 3 is a second perspective view thereof.

The broken line showing of the remainder of the shoe is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a portion of a shoe sole, as shown and described. 